Paper Title
The Development of Learning Achievement and Mathematical Connection Abilities through Cognitive Guided Instruction (CGI) Combined with the Think-Pair-Share Technique of Grade 10 Students

Abstract
This study is an action research project aimed at improving the learning achievement of Grade 10 students in analytic geometry. The study employs the Cognitive Guided Instruction (CGI) approach combined with the Think-Pair-Share technique, with the objective of ensuring that students achieve a minimum passing score of 70% of the total score. The target group for this research consists of 34 Grade 10 students from Sarakhampittayakhom School, located in Mueang District, Mahasarakham Province, during the second semester of the 2024 academic year. The participants were selected through purposive sampling. The research instruments used in this study include lesson plans based on CGI combined with the Think-Pair-Share technique, a learning achievement test and student interview forms The statistical methods used for data analysis include percentage, mean, and standard deviation. The research findings are as follows: 1) The learning achievement of Grade 10 students after receiving instruction through Cognitive Guided Instruction (CGI) combined with the Think-Pair-Share technique improved across the three action research cycles. In the first cycle, students had an average score of 62.5%. In the second cycle, the average score increased to 68.63%. By the third cycle, students achieved an average score of 78.43%. Keywords - Learning Achievement, Cognitive Guided Instruction (CGI), Think-Pair-Share Technique.